Flotation process



Pntented Mar. 23, 1937 Samuel Lenher, Joseph Lincoln Glllson, and N Charles Titus Mentzer. 1117., Wilmington, DeL,

sssignors to E. I. du Pont de Nemours & Compsny, Won, DeL, acorporation of Delawere No Drawing.

Application June a; 1934, Serial 9 Claims. (01. 209-166) This invention relates to a froth flotation process and more particularly refers to a processwherein minerals are floated by means of sulfonated hydrocarbons either alone or in admixture with other flotation agents.

It is an object'of this invention to float min- I erals by a process which is'more efilcient than those heretofore employed. A further object is to obtain a high quantity and quality concentrate-by a process which utilizes agents heretofore unknown to have flotation properties. A still further objectis to utilize said agents under such conditions that they will be of maximum value. A still further object is to improve upon priorartflotation processes by the addition thereto of certain compounds never before used-for such purposes. Additional objects will become apparent from a consideration of the following specification and claims.

These objects are attained according to the' herein described invention which broadly comprises the use in flotation processes of a sulfonated hydrocarbon while maintaining the hydrogen ion concentration of the circuit within the range of about 5.0 to about 9.0. In a more limited sense the invention pertains to a flotation agent comprising sulfonated alcohols preferably containing at least eight carbon atoms in the molecule. 1 this invention comprises flotation agents which are salts of sulfate esters of normal primary alcohols having from twelve to eighteen carbon atoms in the molecule, and in particular organic salts of said sulfate esters. The invention may be more readily understood by a consideration of the following illustrative examples:

' Example 1 1054 grams of a Travancore, India, beach sand o middlings obtained from magnetic separators were suspended in water. This mlddlings product assayed sillimanite 57%, zircon 4%, cyanite 5%, rutile 14.5%, quartz and miscellaneous 19.5%. To the suspension was added 0.3 gram 5 of the lead sulfate salt of lauryl alcohol, small portions of the lead sulfate salts of myristyl. cetyl and stearyl alcohols also being present. The aforementioned flotation agent was,waterinsoluble so prior to its addition to the flota- 50 tion cell it was dissolved in 25 cc. ethyl alcohoL,

The aforesaidsuspension was agitated and air passed therethrough, the pH of the circuit being maintained at 5.4 during the run.

An (A)- cohcentrate was obtained weighing [6 425 grams and containing 99.5% slllimanite.

The preferred embodiment of.

A (B) concentrate was obtained weighing 104 grams and containing 75% sillimanite.

Tailings weighed; 525 grams and contained about sillimanite.

Example 2 5 1000 grams of the same ore used in Example 1 was suspended in water. To this suspension was added 0.2 gram of the sodium sulfate salt oi lauryl alcohol and 0.2 gram of the sodium sulfate salt of stearyl alcohol, small amounts of the sodium sulfate salts of myristyl and cetyl alcohols also being present.

pH was maintained at 5.4 during. the run.

527 grams of a high quality concentrate were obtained.

The tailings weighed 473 grams and contained about 12% silllmanite.

Example 3 Example 2 was repeated substituting for the flotation agents used therein 0.6 gram of cal cium amyl sulfate. Practically no froth was obtained upon agitation. Only one gram of concentrate was produced, and the quality of this concentrate was practically the same as that of the original ore.

This example was repeated increasing the pH value of thecircuit up to8.4. However, no improvement in the frothing or concentrate of the ore was noted.

Example 4 1000 grams of a lead-zinc sulfide ore from Field, British Columbia, containing 13.84% lead and 12.39% zinc was suspended in water. To this suspension was added the following reagents:

1.5 grams sodium carbonate,

0.05 gram of the sodium sulfate salts of cetyl, oleyl and stearyl alcohols,

0.20 gram of sodium cyanide,

4 drops of oleyl alcohol and 3 drops of a mixture of primary and secondary alcohols and some ketones,'the average number of carbon atoms in this mixture being about 7.

The resulting suspension was agitated and 300 grams of a concentrate obtained which assayed 44.1% lead and 21.3% zinc.

To the flotation cell was then added the following reagents: 0.5 gram copper sulfate, 4 drops oleyl alcohol, 4 drops of a mixture of primary and secondary alcohols andketones averaging about ,seven carbon atoms to the molecule and 0.05 gram of the sodium sulfate salts or cetyl, stearyl and oleyl alcohols.

sion was agitated. The concentrate weighed 241 grams assaying 2.18% lead and 22.4% zinc.

, The tailings weighed 459 grams and assayed 5 1.5% lead and 1.30% zinc.

Example 5 Example 6 A pulp was made with 1000 grams of copper sulfide ores of the Ray Consolidated Mine, Ray, Arizona,- containing 2.92% copper. To this pulp was added 1.5 grams of sodium carbonate and 0.08 gram of pine oil.

The pH was maintained at 7.0 during the run.

35 gramsof concentrate were obtained assaying 14.60% copper.

Example 7 The preceding example was repeated substituting 0.05 gram of calcium amyl sulfate for the pine oil referred to therein, all other conditions being maintained exactly the same.

20 grams of concentrate were obtained assaying 13.88% copper.

Example 8' The preceding example was repeated substituting 0.05 gra.n of the sodium sulfate salt of lauryl alcohol for the calcium amyl sulfate referred to therein.

The concentrate weighed 56 grams and assayed 22.4% copper.

Example 9 1000 grams of bituminous coal containing 8.81% ash were suspended in water. To this suspension was added 0.18 gram of the sodium sulfate salt of lauryl alcohol.

The pH during the run was maintained at about 7.0.

The following concentrates were obtained Cleaner concentrate (A) 503 grams, containing 4.11% ash. Cleaner concentrate (B) 287 grams, containing 7.21% ash. Cleaner tails (A) 137 grams, containing 13.46% ash. Cleaner tails (B) 9 grams, containing 56.51% ash. Rougher tails 53 grams, containing 43.73% ash.

Example 10 1000. grams of Alabama about 62.5% barium sulfate were suspended in 65 water. To this suspension was added 0.05 gram of the true sodium sulfonate salt of lauryl alcohol.

The pH during the run was maintained at 7.4.

603 grams of concentrate were obtained containing about 98% barium sulfate.

barytes containing Example 11 The previous example was repeated substituting 0.05 gram of the mono-methylPcyclohexy-lamine sulfate salt of laurylalcohol for the sodiumsulfonate salt of the same alcohol usedtherein- This suspen- The concentrate weighed 624 grams and contained about 98% barium sulfate.

The tails were practically stripped of barytes.

It is to be understood that the aforementioned experiments are illustrative merely of the present invention. Numerous other flotation agents or mixtures thereof as well as innumerable ores may be substituted in these examples without departing from the scope of the present invention. For instance, in place of the sulfate salts of the alcohols referred to sulfate salts of other alcohols may be used. Among these alcohols mention may be made of cetyl, stearyl, octyl, decyl, oleyl. ricinoleyl and linoleyl alcohols. In addition thereto alcohols containing more than one hydroxy group and/or branched-chains may be used as sources of these sulfonated compounds. Mention might here be made of the fact that where reference is made herein to sulfonated hydrocarbons this is meant to include both true sulfonates and sulfate esters of said hydrocarbons.

While the aforementioned sulfonated alcohols are preferred it is to be understood that the sulfonated compounds utilized herein may be derived from other sources, for example olefines, di-oleiines and hydrocarbons having one or more commonly occurring groups substituted thereon such as the amino, halogen and nitro groups. Furthermore, fatty acids corresponding to said alcohols and/or to the substituted derivatives thereof may be used in place thereof or in addition thereto. 1

After sulfonation of the aforementioned hydrocarbons it is advisable to neutralize the sulfonated products with salt-forming constituents. These constituents may be .of inorganic or organic origin. Among the salts of inorganic origin mention may be made of the lead, copper, iron, manganese, magnesium, sodium, potassium, calcium, ammonium, lithium, barium, nickel, tin, etc. These salts may be either water-soluble or water-insoluble. Where they are water-insoluble it is in general advisable todissolve or suspend them in an organic liquid, preferably alcohols containing less than eight carbon atoms, although analogous ketones, ethers, esters and aldehydes may also be used in place thereof or in admixture therewith.

Salt-forming constituents of. organic origin have been found to be particularly suitable for the flotation of ores. Thesesalt-forming constituents are preferably amines of either aliphatic or cyclic character. Compounds representing this class of c0nstituents are, for example, pyridine, piperidine, triethanolamine,, methylamine, dimethylamine, trimethylamine, cyclohexylamine, mono-methyl-cyclohexylamine, etc.

The aforementioned particularly satisfactory flotation agentsmay be represented by the following general formula:

wherein R represents a radical containing a hydrocarbon group of atleast 8 carbon atoms, X represents a sulfuric acid or sulfonic acid group, and Y represents the residue of an organic salt forming compound. In the preferred embodiment thereof R represents the residue of a normal primary alcohol containing from 12 to 18 carbon atoms, Xrepresents a sulfuric acid group, and Y represents the residue of an organic amine.

In the flotation oi ores according to the present invention it is desirable that the hydrogen ion concentration of the circuit be maintained within the range of about 5.0 to about 9.0. If the pH i value of the circuit is reduced it has been observed that the froth becomes stronger. Consequently, in order to float a difficulty floatable ore it is ordi- 5 narily advisable to utilize a low pH, in some cases a pH sumclently low to be within the acid range. n the other hand, where the ore is easily floatable it may readily be separated from other ores by utilizing a high pH value.

The present invention is applicable ,to numerous minerals, contained in both sulfide and nonsulfide ores. For example, it may be applied to the following representative ores:

Barytes, fluorspar, sillimanlte, and other nonlo sulfide ores.

Coal, both bituminous and anthracite. Sulfide ores of copper, zinc, lead, iron, nickel, cobalt, molybdenum and other sulfide ores.

Arsenides, antimonides, tellurides, and suite 220 salts of the metals.

carbonates, sulfates, tungstates. molybdatesf 30 aforesaid sulfonated hydrocarbons may be used in admixture with said prior art flotation agents.

This is particularly true in the case of the sulilde agents. Such sulfide agents, as is well known, are ordinarily mercaptans, xanthates, as carbamates, etc. In using such customary sul-= fide flotation agents it has been found that their efilciency is surprisingly increased by the addition thereto of a small amount of the sulfonated laydrocarbons referred to herein, in particular salts 40 of sulfate estersof normal primary alcohols containing from twelve to eighteen carbon atoms.

The amount of sulfonated hydrocarbon utilized according to the present invention will, of course, depend to a great extent upon the particular ore 45 to be treated and the other reagents which are to be used. In general, it may be stated that the amount will vary from about 0.001% to about 0.2%, based upon the weight of ore to be floated.

For optimum results under a wide variety of con- 50 ditions an amount of sulfonated hydrocarbon approximately midway between these limits will ordinarily be more satisfactory than either extreme.

The present invention permits the flotation of both sulfide and non-sulfide ores in a much more eflioient manner than was heretofore possible. It permits prior art flotation agents to be improved or to be entirely replaced by compounds which were previously unknown for this purpose. Likewise, it permits flotation processes which were defective for various reasons to be revived and operated at a minimum of. expense and with the production of a high quality concentrate. In accordance with this invention minerals which formerly were diflicult or almost impossible to separate may be readily and economically obtained in a concentrated form.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as deflnedin the appended claims.

We claim:

7 l. A process for the froth flotation of ores which comprises frothing a suspension of ore in the presence of a flotation agent having the following general formula:

wherein R represents the residue of a normal primary alcohol containing at least 0 carbon of ores atoms, X represents a sulfonic acid or sulfuric acid group, and Y represents the residue of an organic amine.

4. A process for the froth flotation of ores which comprises frothing an aqueous suspension of ore in the presence of a flotation agent having the following general formula:

l't-X-Y wherein R represents the residue of a normal primary alcohol containing from 8 to 18 carbon atoms, X represents a sulfonic acid or sulfuric acid group, and Y represents the residue of an organic amine, the pH of the circuit being maintained within the range of about 5.0 to about 9.0

during said operation.

5. A process for the froth flotation of minerals which comprises agitating and aerating an aqueous suspension of minerals in the presence of a flotation agent having the following general formula:

R-OSOs-Y wherein It represents the residue of a normal primary alcohol containing from 8 to 18 carbon atoms, and Y represents the residue of an organic amine, the pH of the circuit being maintained within the range of about 5.0 to about 9.0 during said operation.

6. In a froth ,flotation process wherein an aqueous suspension of minerals is agitated andaerated in the presence of flotation agents the step which comprises conducting said operation in the presence of an agent having the following general formula:

wherein R represents the residue of a normal primary alcohol containing from 8 to 18 1 carbon atoms, and Y represents the residue of an organic amine.

7. A process for the froth flotation of minerals which comprises agitating and aerating an aqueous suspension of minerals in the presence of a water-soluble flotation agent having the following general formula:

wherein R represents the residue of a normal primary alcohol containing from 12 to 18 carbon atoms, and Y represents the residueof an organic amine, the pH of the circuit being malnduring said operation.

8. A process for the froth flotation of minerals which comprises agitating and aerating an aque tained within the range of about 5.0 to about 9.0

R-OSOa-Y wherein R represents the residue of a normal pri- 'rnary alcohol containing from 12 to 18 carbon atoms, and Y represents the residue of a cyclohexyiamine, the pH of the circuit being maintained within the range of about 5.0. to about 9.0 during said operation.

9. A process for the froth flotation 01 minerals which comprises agitating and aerating an vaqueous suspension of minerals in the presence oi! the mono-methyl-cyclohexylamine sulfate salt of lauryl alcohol, the pH of the circuit being maintained within the range of about 5.0 to about 9.0 during said operation.

SAMUEL LENHER. JOSEPH L. GILLSON. CHARLES TITUS MEN'IZER, JR. 

